Application of CFD Techniques to Assess Spontaneous Heating/Fire during Extraction of Thick Coal Seam Using Blasting Gallery (BG) Method

Mohalik, N.K.; Khan, Asfar Mobin; Ray, S. K.; Mishra, Debashish; Varma, N. K.; Singh, Ran Vijay; Singh, Pradeep K.

doi:10.1080/00102202.2019.1624540

Cited by 5 publications

(2 citation statements)

References 1 publication

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“…The safety of coal production has been greatly improved with the development of longwall mining in China, while this also brings several safety problems, like the frequent occurrence of spontaneous combustion of coal in the goaf due to severe air leakage and a large amount of coal leaving [1][2][3][4][5]. To control spontaneous combustion of residual coal in longwall goaf, many techniques like grouting, inert gases injection and gel and foam injection have been developed and applied [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

The Application of Nitrogen Curtain Technology to Longwall Goaf to Prevent the Spontaneous Combustion of Coal: A Case Study in Shajihai Coalmine, China

Geng,

Zhao,

Liu

et al. 2023

Fire

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To enhance the inerting effect of nitrogen on large longwall goaf, a novel goaf-inerting method of using a full cross-section nitrogen curtain for a U-shaped ventilation working face is developed. The working principle of the full cross-section nitrogen curtain is elucidated. The design principle and key parameters of the nitrogen curtain needed to achieve an optimum nitrogen injection effect are established. The nitrogen curtain technology is successfully applied to the scenario of fire prevention in the underground goaf. The field study shows that the full cross-section curtain injection of nitrogen exhibits many advantages such as simple operation and homogeneous diffusion. The implementation of the nitrogen curtain reduced the maximum width of the goaf oxidation zone from 70 m to 20 m. And the CO concentration in the upper corner decreased from 21.8 ppm to 11.2 ppm after 18 h of nitrogen injection. After 48 h of injection, the CO concentration in the upper corner remained unchanged and the concentration had reduced to 0 in the lower corner. It was demonstrated that the inerting efficiency of the full cross-section nitrogen curtain reached 86% in the upper corner and 100% in the lower, which is significantly superior to the traditional buried-pipe nitrogen injection method. The effect verifies the effectiveness of the curtain injection method of nitrogen, which can ensure a safe working face production.

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Section: Introductionmentioning

confidence: 99%

The Application of Nitrogen Curtain Technology to Longwall Goaf to Prevent the Spontaneous Combustion of Coal: A Case Study in Shajihai Coalmine, China

Geng,

Zhao,

Liu

et al. 2023

Fire

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“…If the external conditions result in destroying the heat-storage capacity of the coal body during this process, coal cooling is promoted, resulting in “oxidized coal” formation. The problem of spontaneous combustion of oxidized coal is common in the process of coal mining and utilization such as mining or re-mining of the residual coal in the goaf; , after anaerobic cooling in the closed fire zone, , after the coalfield fire area is extinguished, around the burning area; − in the process of slicing mining in thick coal seams, or for the upper-slice coal body exposed again under the influence of lower-slice mining. , Therefore, it is of great significance to study the macroscopic and microscopic characteristics of the oxidized coal spontaneous combustion process for efficient prevention of reburning of the oxidized coal.…”

Section: Introductionmentioning

confidence: 99%

Combustion Kinetics and Mechanism of Pre-Oxidized Coal with Different Oxygen Concentrations

et al. 2021

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The phenomenon of spontaneous combustion of “oxidized coal” is common in mining processes of goafs, thick coal seams, and unsealing of closed fire areas. In order to study the reburning characteristics of coal with different oxidation degrees, the oxygen concentration in the pre-oxidation process was selected as the key influencing factor. Thermogravimetric analysis (TGA) and in situ Fourier-transform infrared (FT-IR) spectroscopy were used to study the macro- and microcharacteristics of raw and oxidized coal during the combustion stage. The results showed that the pre-oxidation treatment exhibited a dual effect on promoting and inhibiting the weight loss characteristics of oxidized coal. The apparent activation energy, E a, of the combustion reaction for the utilized coal samples was calculated using the Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) methods, and it was found that the average apparent activation energy (E a̅) values of the oxidized coal samples were less in magnitude than that of the raw coal and that the coal sample with the pre-oxidized oxygen concentration of 15% was more prone to the combustion reaction. Using the correlation determination method of key active groups in the proposed coal combustion reaction, the key active groups affecting the weight change of the tested coal samples during the combustion stage were determined as −CH3 and C–O. The results can be helpful to prevent and control coal spontaneous combustion during re-mining and unsealing of closed fire areas.

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Causes and detection of coalfield fires, control techniques, and heat energy recovery: A review

Zhou

Shi

et al. 2020

Int J Miner Metall Mater

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Application of CFD Techniques to Assess Spontaneous Heating/Fire during Extraction of Thick Coal Seam Using Blasting Gallery (BG) Method

Cited by 5 publications

References 1 publication

The Application of Nitrogen Curtain Technology to Longwall Goaf to Prevent the Spontaneous Combustion of Coal: A Case Study in Shajihai Coalmine, China

The Application of Nitrogen Curtain Technology to Longwall Goaf to Prevent the Spontaneous Combustion of Coal: A Case Study in Shajihai Coalmine, China

Combustion Kinetics and Mechanism of Pre-Oxidized Coal with Different Oxygen Concentrations

Causes and detection of coalfield fires, control techniques, and heat energy recovery: A review

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